Harkin Institute
The Harkin Institute for Public Policy & Citizen Engagement is a nonpartisan public policy research institute at Drake University in Des Moines, Iowa. In the summer of 2021, I was commissioned to reconceive an existing stormwater retention planting that needed redirection. The project presented an opportunity for a more generous and expansive concept befitting the institute’s commitment to inclusive policymaking. The commission was developed in two phases; a small 2,000 sqft detention basin was installed in 2021, followed by two larger bioswales and a buffer island totaling nearly 6,000 sqft in 2022.
While tempting to wipe the slate and start fresh, I preserved the existing serviceberry trees (Amelanchier) and replaced the understory with approximately 30 native species and selections adapted to occasional inundation and runoff. The three levels of the basin architecture, coupled with a skewed planting grid, afforded the chance to create something lush and immersive from all perspectives, chiefly the building's main lobby and entrance.
When designing a bioswale in a four-sided depression, I considered how water interacts with the constructed topography and what this required of the planting palette. Even in the relatively small detention basin (2,000 sqft), I planned for three zones of inundation ranging from deeply saturated in the basin to mesic at the sidewalk edge with water simply moving over the surface. The photos illustrate the transition between the three featuring Asclepias incarnata (swamp milkweed), an aptly named wet-footed and short-lived perennial; Rudbeckia fulgida var. deamii (Deam's black-eyed Susan), a native of woodland edges and stream banks; and Agastache foeniculum (anise hyssop), broadly adapted to horticultural conditions but natively found on sloped, dry-mesic clearings and meadows with a recent history of disturbance. Connecting the habitat profiles of these plants to their application was critical for building a resilient plant community.
If there’s a big bullet point takeaway from this project, let it be that we should normalize lush, verdant bioswales. Our cities need green infrastructure vegetation to mitigate stormwater runoff, cool our surroundings and provide habitats and resources, not simply mulched medians with curb cuts and a few sedges or grasses planted 18 inches on center. Vegetation is the surface of the lived experience in urban environments and should be an equal partner to the development of public space.
I directed and installed the landscape in collaboration with Jeff Reiland of Abundant Designs (Waukee, Iowa) in early October 2021. Most images here were taken in 2022 and 2023.
